The present invention relates to a device for adjusting the position of a strap return element in particular of a safety belt for an automobile vehicle.
In most vehicles, this strap return element is disposed on an anchoring pin fixed to the body of the vehicle at a height suitable for the majority of users of so called normal size.
However, this height is unsuitable for some users and in particular persons of small size.
To overcome this problem, a number of devices for adjusting the height of this strap return element are known in the art.
For example a device for adjusting the height of the anchoring point of a safety belt is known from the document FR.2 484 343 in which a slide moves along a screw-threaded support rod in the range of adjustment of the anchoring, said rod being rotatively mounted between the walls of a case fixed to an element of the body of the vehicle. The front side of this slide carries an anchoring member of the belt and its rear side carries an element for preventing the rotation of the slide which guides it along the inner wall of the case.
A device is also known from the document FR 2 488 201 for adjusting the height of a return element of a vehicle safety belt, comprising an adjusting element carrying the return element with a bolt which engages in stop notches of a rectilinear guide, it being possible to disengage the bolt by an actuating mechanism.
A device is also known from the document FR. 2 482 539 for adjusting the anchoring point of a safety belt disposed above the shoulder of an occupant of a vehicle, in which the anchoring point is carried by a slide cursor movably mounted in a slideway and capable of being immobilized by a catch which cooperates with a series of orifices provided in the slideway.
The document FR 2 513 887 discloses a device for adjusting the position and the height of the upper element of the shoulder belt of a safety belt. This device comprises a slideway integral with the body of the vehicle, and provided with a guide slot and openings in which penetrates at least one locking member mounted on a slide which carries the upper element and may be locked and unlocked by a manual actuating means.
The document F 2 543 838 discloses an anchoring device for the upper point of a safety belt, comprising a rail having a plurality of openings which are in two parts, and a locking lug which may be controlled by an actuating button. The adjustment of the position of the anchoring point is achieved by extracting the lug from the opening, shifting the slide and reintroducing the lug in another opening.
Lastly the document FR 2 536 288 discloses a device for adjusting the height of a safety belt for an automobile vehicle, constituted by a guide slideway having on both sides, locking openings disposed one above the other, and a carriage which is movable in the slideway, this carriage carrying a belt fixing or return element and including stop members which may be transversely shifted relative to the direction of movement of the carriage by means of a control member in opposition to the action of a spring for passing from a locking position to an unlocking position.
However, all these devices have a number of drawbacks, in particular as concerns the possibilities of adjustment, their relatively complex structure and consequently their relatively high manufacturing and assembly costs.
Furthermore, in most of the known devices, the locking means are biased to their locking position by elastic means which exert thereon a relatively large maintaining force. This obliges the user who wishes to shift the strap return element to exert on the means for shifting these locking means a relatively large force for shifting the locking means to their retracted position and thereby permit the shifting of the strap return element.